Start Date: Jul 26, 2007
End Date: Jul 25, 2012
To identify and characterize factors affecting nutrient use efficiency in cattle, resources will be developed including a phenotypic database of dairy efficiency and corresponding DNA and tissue collections, methods for live animal intestinal tissue collection suitable for gene expression studies, and sub-populations of dairy cattle to investigate inflammation and nutrient use interactions. Novel DNA sequencing technology will also be evaluated for its utility in characterizing changes in rumen microbial populations during rumen development. Transcript profiling techniques including microarray and quantitative real-time PCR will be used to establish molecular markers of proliferation, development and differentiation of the bovine gastrointestinal tract, and to identify metabolic and hormone pathways controlling nutrient metabolism in the ruminant gastrointestinal tract. Finally, two dietary strategies that potentially affect the rumen microbial population and production efficiency will be studied for their effects on nutrient use efficiency in cattle.